Drying-machine



(No Model.)

J, B. DOBSON. DRYING MACHINE.

Patented Jan. 30, 1894.

. B is the water discharge pipe D.

l UNITED STATES PATENT Fries.

JOHN-B. DOBSON, OF PHILADELPHIA, PENNSYLVANIA.

DRY'l-NGTMACHINE.

SPECIFICATION forming part of Letters Patent No. 513,896, dated January so, 1894.

Application filed August 24, 1893. Serial No. 4331958 (N0 model- To all whom it may concern:

Be it known that I, JOHN B. DOBSON,a citizenof the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Drying-Machines, of which the following is a specification.

The object of my invention is to remove the water of vcondensation from the interior of all the drying cylinders used for drying paper, cloth, dac., without causing back pressure in the steam pipes, and Without wasting the steam to any great extent. This object I attain in the following manner, reference being had to the accompanying drawings, in which- Figure 1, is a side view illustrating my im-V proved draining system, the bearings Y and frames of the machine being removed to avoid confusion. Fig. 2, is asectional view of a portion of a drying cylinder and the pipes, the section being on the line 1-2, Fig. 1.

A are the drying cylinders arranged generally in series as shown, and around which the paper or cloth is passed. The cylinders A are hollow, and theshell is made as thin as possible, so that the steam within the cylin der will readily dry the paper or cloth. Water of condensation, however, quickly accumulates in these cylinders, and if this water is not removed regularly, it will accumulate and tend to cool the cylinders and cause them to sweat, and in many cases mark the paper, but by my invention the water of condensation is removed regularly from each'cylinder.

B is the steam inlet pipe communicating with a live steam pipe B extending, preferably, the full length of the machine. This live steam pipe B is connected to the steam inlet ct of each cylinder by pipe b, clearly shown in Fig. 2, so that the'live steam will readily iiow into the cylinders.

Running parallel with the live steam pipe This pipe is connected with the live steam pipe at one end by an equalizing'pipe e and is connected to a trap E at the opposite end by a pipe e; an equalizing pipe e2 connects the live steam pipe B also to the trap. This trap has an ordinary valve fand is connected to a discharge pipe F which carries olif the water of condensation. The steam pipe B' being connected at both ends .to the drainage pipe, Water of condensation cannot back up in said steam pipe and prevent the steam entering the cylinders as is the casein the majority of paper drying machines as now constructed. The equalizing pipe e drains the steam pipe B so that only dry steam will be admitted to the cylinders. The valvefof the trap E is controlled by a lioat f which lifts the valve when the water of condensationin the device reaches a certain level.

Extending up from the pipe D is a series vot' outlet pipes d which pass into the cylinder through the stuffing box a in the head of the cylinder, and each pipe d has an extension d terminating at a point near the bottom of the cylinder, forming the short leg of a siphon, the pipe d forming the long leg. The pipe d may be enlarged at d2 as shown by dotted lines in Fig. 2 to increase the steam space between the water level in the pipe d and the cylinder, so that when the water in the cylinder closes the mouth of the pipe o3 the quantity of steam in the pipe dwill condense, forming a partial vacuum and water in the cylinder will be ldrawn through the short leg of the siphon unti-l the water level in the cylinder is below the mouth of the pipe breaking the siphon. Thus it will be seen that the exhaust pipe of each cylinder acts independently, as there is practically no connection between the vacuum spaces of the exhaust pipes. The water level in the several pipes will be yraised by the admission of water from the several cylinders, and when it reaches a certain level the valve of the trap will open,

and the water will flow out through the pipe F. The valve will close when the water reaches a certain low level, andthe operation will be repeated. Thus it will be seen that high pressure steam is not required for the cylinders, as I do not rely upon the action of the live steam to force the Water out of the cylinders, but rely on the condensation of steam in the exhaust pipe to start the Siphon.

I claim as my invention;`

1. The combination of the drying cylinder, the steam inlet, and the discharge pipe for the water of condensation, said discharge pipe extending near to the bottom of the cylinder, and having its outer end water sealed, so that when the water in the cylinder closes the mouth of saidpipe the steam in the pipe will be condensed, formingapartialvacuum,which IOO will start the siphon discharge, substantially as described.

2. The combination of the drying cylinders of a drying machine, the inlet steam pipe, the outlet pipe for the Water of condensation, said pipes being connected together, and to a steam trap, steam' inlet pipes extending from the said steam pipe to the cylinder, and water exhaust pipes extending from each cylinder to the outlet pipe, the Whole being constructed so that Water will remain at acertain level in each exhaust pipe, substantially as described.

3. The combination of the drying cylinders, an inlet pipe b and an exhaust pipe d for each cylinder, a steam pipe B coupled to said steam inlet pipe, and a water outlet pipe D coupled to each exhaust pipe, said steam pipe B and water outlet pipe D being connected together at each end, a trap connected to said pipes, to form a water level in each exhaust pipe, so that when the water accumulates in any one of the cylinders, it will trap the steam in the exhaust pipe, substantially as specified.

4. The combination of the steam inlet pipe, the waterdischarge pipe coupled together and to a trap so as to equalize the pressure, drying cylinders, steam inlet pipe extending from the steam pipe to the drying cylinder, exhaust pipes for the Water of condensation, extending from the cylinders to the water pipe, said exhaust pipe being enlarged above the Water level so as to form an increased steam space, substantially as described.

5. The combination of the steam inlet pipe, the exhaust pipe for the water of condensation, said exhaust pipe being belowr the steam inlet pipe, a drying cylinder, a pipe extending from the steam inlet pipe to the drying cylinder and a pipe extending from the cylinder to the exhaust pipe, with a coupling pipe extending from the steam inlet pipe down to the exhaust pipe so that the steam inlet pipe is free from Waterot' condensation, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN B. DOBSON.

Vitnesses:

H. F. REARDoN, HENRY IIoWsoN. 

